Investments - Summary of Selected Financial Information for Jefferies Finance (Detail) - Jefferies Finance, LLC [Member] - USD ($) $ in Millions |
May 31, 2016 |
Nov. 30, 2015 |
|---|---|---|
| Schedule of Equity Method Investments [Line Items] | ||
| Total assets | $ 7,056.1 | $ 7,292.1 |
| Total liabilities | 6,140.2 | 6,297.3 |
| Total equity | 915.9 | 994.8 |
| Our total equity balance | $ 458.0 | $ 497.4 |